Recently, as automation of control advances, there is increasing demand for safety and reliability of electronic control devices. To secure safety of electronic control devices, it is demanded that, when an abnormality occurs, the abnormality should be detected and operation should be stopped immediately. Moreover, not only the immediate stop of operation when a failure occurs, but also continuation of normal operation has come to be demanded.
The PTL 1 below describes a control system in which, if a failure occurs in one phase of driving circuits corresponding to three phases for driving a brushless motor, the driving circuits corresponding to the remaining two phases continue driving the motor.